High voltage control system and fault control method

Abstract

A high-voltage control system and a fault control method, the high-voltage control system comprising: a driving high-voltage circuit, an accessory high-voltage circuit connected in parallel with the driving high-voltage circuit, and a charging high-voltage circuit connected to the rear end of the accessory high-voltage circuit, the driving high-voltage circuit comprising a battery unit, a driving load unit, and a driving pre-charging unit and a driving total positive relay connected in parallel between the driving load unit and the positive electrode of the battery unit; the accessory high-voltage circuit comprises an accessory unit connected to the negative electrode of the battery unit, and an accessory total positive relay and an accessory pre-charging unit connected in parallel between the positive electrode of the battery unit and the accessory unit; the charging high-voltage circuit comprises a slow charging total positive relay and an on-board charging system, the input end and the output end of the slow charging total positive relay are respectively connected to the output end of the accessory total positive relay and the on-board charging system, and the on-board charging system is connected to the negative electrode of the battery unit. The present invention can reduce the probability of the whole vehicle being powered off due to the failure of a single high-voltage component.

Description

Technical Field

[0001] The present invention relates to the field of automobiles, and in particular to a high-voltage control system and a fault control method. Background Art

[0002] Many components in electric vehicles have working voltages of up to several hundred volts and currents of tens or even hundreds of amperes. Therefore, high-voltage power distribution systems are usually introduced in electric vehicles. Among them, the high-voltage power distribution system mainly controls the on-off of electrical equipment driven by high voltage, realizes low-voltage control of high voltage, improves vehicle safety and ensures normal driving of vehicles.

[0003] When designing high-voltage distribution circuits for electric vehicles, all high-voltage components are generally connected in parallel at the rear end of the total positive relay and the total negative relay. When any high-voltage component fails and the high voltage needs to be reduced, the entire vehicle needs to control the entire high-voltage circuit to be disconnected, causing the vehicle to break down and be unable to drive. Summary of the invention

[0004] In view of the above situation, it is necessary to provide a high-voltage power distribution system and fault control method to address the problem in the prior art that when a high-voltage component in a vehicle fails and the high voltage needs to be reduced, the entire high-voltage circuit needs to be disconnected, affecting the use of the vehicle.

[0005] A high voltage power distribution system, comprising:

[0006] A driving high-voltage circuit, comprising a battery unit, a driving load unit connected to the negative electrode of the battery unit, and a driving pre-charging unit and a driving total positive relay connected in parallel between the driving load unit and the positive electrode of the battery unit, wherein the driving pre-charging unit is used to provide a pre-charge amount to the driving load unit;

[0007] an accessory high-voltage circuit connected in parallel with the driving high-voltage circuit, comprising an accessory unit connected to the negative electrode of the battery unit, and an accessory main positive relay and an accessory pre-charging unit connected in parallel between the positive electrode of the battery unit and the accessory unit, the accessory pre-charging unit being used to provide a pre-charge amount to the accessory unit;

[0008] A charging high-voltage circuit is connected to the rear end of the accessory high-voltage circuit, and includes a slow-charging total positive relay and an on-board charging system. The input and output ends of the slow-charging total positive relay are respectively connected to the output end of the accessory total positive relay and the on-board charging system. The on-board charging system is connected to the negative electrode of the battery unit. The driving load unit includes a high-voltage component for driving the vehicle, and the accessory unit includes a high-voltage component in a vehicle accessory.

[0009] Furthermore, the above-mentioned high-voltage control system also includes a total negative relay, one end of which is connected to the battery unit, and the other end is respectively connected to the input end of the driving load unit, the accessory unit and the vehicle charging system.

[0010] Furthermore, in the above-mentioned high-voltage control system, the running pre-charging unit includes a running pre-charging relay and a running pre-charging resistor connected in series, the running pre-charging relay is connected to the battery unit, and the running pre-charging resistor is connected to the running load unit.

[0011] Furthermore, in the above-mentioned high-voltage control system, the accessory pre-charging unit includes an accessory pre-charging relay and an accessory pre-charging resistor connected in series, the accessory pre-charging relay is connected to the battery unit, and the accessory pre-charging resistor is connected to the accessory unit.

[0012] Furthermore, the above-mentioned high-voltage control system also includes a plurality of fuses, and the plurality of fuses are respectively connected to the input ends of the plurality of high-voltage accessories.

[0013] Furthermore, in the above-mentioned high-voltage control system, the travel load unit includes an MCU and a motor connected to the MCU.

[0014] Furthermore, in the above-mentioned high-voltage control system, the accessory unit includes a DC / DC converter, an air-conditioning electric heater, an air-conditioning compressor and a battery heater.

[0015] The present invention further provides a fault control method, which is applied to any one of the above-mentioned high-voltage control systems, and the fault control method comprises:

[0016] Check whether the charging gun is connected;

[0017] When the charging gun is not connected and it is detected that the vehicle needs to be powered on, the driving high-voltage circuit and the accessory high-voltage circuit are powered on respectively;

[0018] When the driving high-voltage circuit fails to be powered on and the accessory high-voltage circuit is powered on successfully, the vehicle is controlled to enter a driving high-voltage prohibition mode, wherein the driving high-voltage prohibition mode is used to control the driving high-voltage circuit to be disconnected and the motor output torque to be zero;

[0019] When the driving high-voltage circuit is powered on successfully and the accessory high-voltage circuit fails to be powered on, the vehicle is controlled to enter an accessory high-voltage prohibition mode, wherein the accessory high-voltage prohibition mode is used to control the accessory high-voltage circuit to be disconnected and control each high-voltage accessory in the accessory unit to be shut down;

[0020] When both the driving high-voltage circuit and the accessory high-voltage circuit fail to be powered on, the entire vehicle is controlled to enter a mode of disabling all high-voltage circuits, wherein the mode of disabling all high-voltage circuits is to control all high-voltage circuits to be disconnected and all high-voltage components to be shut down.

[0021] Furthermore, the above fault control method further includes:

[0022] When the charging gun is connected and it is detected that the vehicle needs to be powered on, the charging high-voltage circuit is powered on;

[0023] When the charging high-voltage circuit is powered on successfully, the accessory high-voltage circuit is powered on;

[0024] When the charging high-voltage circuit fails to be powered on, the vehicle is controlled to enter a charging high-voltage prohibition mode, wherein the charging high-voltage prohibition mode is used to control the charging high-voltage circuit to be disconnected;

[0025] When the charging high-voltage circuit is powered on successfully and the accessory high-voltage circuit fails to be powered on, the entire vehicle is controlled to enter the all-high-voltage mode.

[0026] Furthermore, the above fault control method further includes:

[0027] When the driving high-voltage circuit and the accessory high-voltage circuit are both powered on successfully, real-time detection is performed to determine whether there are faults on the driving high-voltage circuit and the accessory high-voltage circuit that require high voltage reduction;

[0028] When a fault that requires high pressure is present in the driving high pressure circuit, the vehicle is controlled to enter the driving high pressure prohibition mode;

[0029] When a fault occurs in the accessory high-voltage circuit that requires high voltage to be lowered, the entire vehicle is controlled to enter the accessory high-voltage prohibition mode.

[0030] The present invention can reduce the probability of the whole vehicle losing power due to the failure of a single high-voltage component, thereby improving vehicle reliability and customer experience. In addition, in charging mode, high voltage is applied only to charging-related accessories, while the driving high-voltage components MCU and motor are not applied, which truly realizes the interlocking of charging and driving functions from a physical level, avoiding the high-voltage risk of accidentally triggering the driving function during charging and causing the charging line to be broken. In addition, since the three high-voltage circuits can be connected or disconnected separately, when troubleshooting insulation faults, the source of the insulation fault can be quickly checked by disconnecting one or two of the high-voltage circuits. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of the circuit structure of the high-voltage control system in the first embodiment of the present invention;

[0032] Figure 2is a flow chart of a fault control method in a second embodiment of the present invention;

[0033] Figure 3 A flowchart of a failure mode in a non-charging state in one embodiment of the present invention;

[0034] Figure 4 is a flow chart of a fault control method in a third embodiment of the present invention;

[0035] Figure 5 A flowchart of a failure mode in a non-charging state in one embodiment of the present invention;

[0036] Figure 6 Flow chart of a high voltage power-down method in a non-charging state according to a fourth embodiment of the present invention;

[0037] Figure 7 It is a flow chart of a high voltage power-down method in a charging state in a fifth embodiment of the present invention;

[0038] Figure 8 It is a flow chart of insulation fault troubleshooting in the non-charging state of the present invention;

[0039] Fig. 9 This is a flow chart of insulation fault troubleshooting in the charging state of the present invention.

[0040] Main component symbols

[0041] DETAILED DESCRIPTION

[0042] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0043] These and other aspects of the embodiments of the present invention will become clear with reference to the following description and drawings. In these descriptions and drawings, some specific implementations of the embodiments of the present invention are specifically disclosed to represent some ways of implementing the principles of the embodiments of the present invention, but it should be understood that the scope of the embodiments of the present invention is not limited thereto. On the contrary, the embodiments of the present invention include all changes, modifications and equivalents that fall within the spirit and connotation of the appended claims.

[0044] See also Figure 1, is a high-voltage control system in an embodiment of the present invention, which is applied to electric vehicles. By controlling the connection and disconnection of relays, the power-on pre-charging process and high-voltage electric energy distribution of various high-voltage components are coordinated to improve the safety of the vehicle and ensure the normal driving of the vehicle. The high-voltage control system includes three high-voltage circuits, namely, a driving high-voltage circuit, an accessory high-voltage circuit, and a charging high-voltage circuit.

[0045] The driving high-voltage circuit includes a battery unit 10 , a driving load unit 11 connected to the negative electrode of the battery unit, and a driving pre-charging unit and a driving total positive relay 12 connected in parallel between the driving load unit 11 and the positive electrode of the battery unit 10 .

[0046] The driving load unit 11 includes high-voltage components for driving the vehicle, such as an MCU and a motor connected to the MCU. The battery unit 10, the driving pre-charging unit, the driving total positive relay 12 and the driving load unit 11 are connected to form a driving high-voltage circuit for high-voltage control of driving-related high-voltage components.

[0047] The driving pre-charging unit is used to provide a pre-charging amount to the driving load unit 11 , and includes a driving pre-charging relay 13 and a driving pre-charging resistor 14 connected in series. The driving pre-charging 13 is connected to the battery unit 10 , and the driving pre-charging resistor 14 is connected to the driving load unit 11 .

[0048] The accessory high-voltage circuit is connected in parallel with the driving high-voltage circuit, and includes an accessory unit 21 connected to the negative pole of the battery unit 10 , and an accessory main positive relay 22 and an accessory pre-charging unit connected in parallel between the positive pole of the battery unit 10 and the accessory unit.

[0049] The accessory unit includes high-voltage components in vehicle accessories, such as a DC / DC converter (DC / DC), a PTC heater, an AC compressor (AC), and a battery heater, etc., and each high-voltage component is connected in parallel. The battery unit 10, the accessory total positive relay 22, the accessory pre-charge unit, and the accessory unit 21 form an accessory high-voltage circuit for controlling the high and low voltages of the accessory unit 21.

[0050] The accessory pre-charging unit includes an accessory pre-charging relay 23 and an accessory pre-charging resistor 24 connected in series. The accessory pre-charging relay 23 is connected to the battery unit 10 , and the accessory pre-charging resistor 24 is connected to the accessory unit 10 . The accessory pre-charging unit is used to provide a pre-charging amount to the accessory unit 21 .

[0051] The charging high-voltage circuit is connected to the rear end of the accessory high-voltage circuit, and includes a slow-charging total positive relay 31 and an on-board charging system (OBC) 32. The input and output ends of the slow-charging total positive relay 31 are respectively connected to the output end of the accessory total positive relay 22 and the on-board charging system 32, and the on-board charging system 32 is connected to the negative electrode of the battery unit 10.

[0052] The on-board charging system 32 is a high-voltage component used for charging in an electric vehicle, and the charging high-voltage circuit is used for high and low voltage control of the on-board charging system.

[0053] In the high-voltage control system of this embodiment, the driving high-voltage circuit can be controlled to be connected and disconnected independently; the accessory high-voltage circuit can also be connected and disconnected independently; the charging high-voltage circuit is connected to the rear end of the accessory high-voltage circuit. When the accessory high-voltage circuit is connected, the charging high-voltage circuit can be connected or disconnected. When the accessory high-voltage circuit is disconnected, the charging high-voltage circuit must be disconnected. When the high-voltage component of the accessory high-voltage circuit fails while the vehicle is in driving state, the accessory high-voltage circuit can be disconnected, and the driving high-voltage circuit can remain normally connected to ensure that the vehicle can continue to drive, avoiding the problem of vehicle breakdown caused by non-driving related high-voltage component failure. In addition, it can also solve the problem of being unable to use high voltage for air conditioning cooling and PTC heating due to driving-related high-voltage component failure or charging-related high-voltage component failure when the vehicle is stationary.

[0054] Furthermore, the high-voltage control system also includes a total negative relay, one end of which is connected to the battery unit, and the other end is connected to the driving load unit, the accessory unit, and the input end of the vehicle charging system. The total negative relay is a master control switch for controlling the connection and disconnection of each circuit. It can be understood that when the total negative relay is not used, controlling the relays in each circuit to be disconnected or closed at the same time can achieve the same function of the total negative relay.

[0055] Furthermore, the high-voltage control system further includes a plurality of fuses, which are respectively connected to the input terminals of the plurality of high-voltage components. In this embodiment, a fuse is added in front of each high-voltage component to avoid the risk of excessive current burning the high-voltage component and causing fire caused by a short circuit, so as to protect each high-voltage component.

[0056] Table 1 shows the working status of each high-voltage component in various high-voltage modes. MCU only needs to work in driving mode, OBC only works in charging mode, DC / DC, AC, PTC (including air conditioning PTC and battery PTC) may work in all three modes.

[0057] Table 1. Working status of each high voltage component in different modes

[0058] High voltage components MCU DC / DC AC PTC OBC Driving mode √ √ √ / × √ / × × Static state × √ √ / × √ / × × Charging Mode × √ √ / × √ / × √

[0059] According to the working status of each high-voltage component in different modes analyzed in Table 1, the automobile high-voltage power distribution system is designed into three circuits: the three circuits share a common negative relay. In addition, the driving high-voltage circuit also includes a driving total positive relay, a driving pre-charge relay, and a driving pre-charge resistor; the accessory high-voltage circuit also includes an accessory total positive relay, an accessory pre-charge relay, and an accessory pre-charge resistor; the charging high-voltage circuit also includes a slow charging total positive relay. Since the charging circuit requires the pre-charge and DC / DC discharge functions of the accessory high-voltage circuit, it is arranged at the rear end of the accessory high-voltage circuit.

[0060] This embodiment can achieve the following functions by designing a mutually independent driving high-voltage circuit, an accessory high-voltage circuit, and a charging high-voltage circuit at the rear end of the accessory high-voltage circuit:

[0061] 1) The vehicle can continue to drive when the accessory high-voltage circuit fails;

[0062] 2) When the high-voltage circuit fails during driving, the vehicle can still use high-voltage components such as air conditioning and heater and charge normally;

[0063] 3) When the high-voltage charging circuit fails, the vehicle can still use high-voltage accessories such as air conditioning and heater normally.

[0064] This embodiment can reduce the probability of the whole vehicle being powered off due to the failure of a single high-voltage component, and improve vehicle reliability and customer experience. In addition, in charging mode, only the charging-related accessories are high-voltage, while the driving high-voltage components MCU and motor are not high-voltage, which truly realizes the interlocking of charging and driving functions from a physical level, avoiding the high-voltage risk of accidentally triggering the driving function during charging and causing the charging line to be broken. In addition, since the three high-voltage circuits can be connected or disconnected separately, when troubleshooting insulation faults, the source of the insulation fault can be quickly found by disconnecting one or two of the high-voltage circuits.

[0065] See also Figure 2 , is a fault control method of the high voltage control system in the second embodiment of the present invention based on the above embodiment, and the fault control method is divided into power-on fault control in a non-charging state and power-on fault control in a charging state. The power-on fault control process in a non-charging state includes steps S01 to S06.

[0066] Step S01, detect whether the charging gun is connected, if not, execute step S02.

[0067] Step S02, when it is detected that the vehicle has a power-on demand, the driving high-voltage circuit and the accessory high-voltage circuit are powered on respectively.

[0068] Step S03, determining whether the driving high-voltage circuit and the accessory high-voltage circuit are both powered on successfully.

[0069] In specific implementation, the vehicle determines whether the driving high-voltage circuit and the accessory high-voltage circuit are powered on successfully based on the connection status of the driving main positive relay and the accessory main positive relay fed back by the battery management system. Taking the driving high-voltage circuit as an example, when the battery management system issues a control command to close the driving main positive relay and disconnect the driving pre-charge relay, if the voltage of the rear end of the driving main positive relay to the negative electrode of the battery cell is close to the voltage between the positive and negative electrodes of the battery cell, it is judged that the driving main positive relay is connected and the high voltage is powered on successfully; if this voltage is close to 0, it is judged that the driving main positive relay is not connected and the driving high-voltage circuit fails to be powered on.

[0070] Step S04, when the driving high-voltage circuit fails to be powered on and the accessory high-voltage circuit is powered on successfully, the vehicle is controlled to enter a driving high-voltage prohibition mode. The driving high-voltage prohibition mode is used to control the driving high-voltage circuit to be disconnected, and the motor output torque is zero. In specific implementation, the driving high-voltage circuit can be disconnected after the vehicle speed gradually drops to a preset vehicle speed threshold.

[0071] Step S05, when the driving high-voltage circuit is powered on successfully and the accessory high-voltage circuit fails to be powered on, the vehicle is controlled to enter the accessory high-voltage disabled mode. The accessory high-voltage disabled mode is used to control the accessory high-voltage circuit to be disconnected and each high-voltage accessory in the accessory unit to be shut down. In specific implementation, the accessory high-voltage circuit can be disconnected after the current of the accessory high-voltage circuit drops to a preset current threshold.

[0072] Step S06, when both the driving high-voltage circuit and the accessory high-voltage circuit fail to be powered on, the vehicle is controlled to enter a mode of disabling all high-voltage circuits. The mode of disabling all high-voltage circuits controls all high-voltage circuits to be disconnected and all high-voltage components to be shut down. In the non-charging state, only the driving high-voltage circuit and the accessory high-voltage circuit need to be disconnected, that is, the vehicle is powered off, and all high-voltage components are prohibited from working, and driving is prohibited.

[0073] In this embodiment, the vehicle detects whether a charging gun is connected to the slow charging port. When the charging gun is not connected and there is a need to power on, the driving high-voltage circuit and the accessory high-voltage circuit are powered on in sequence. The process of powering on the driving high-voltage circuit includes:

[0074] Step S12, closing the total negative relay and then closing the driving pre-charge relay;

[0075] Step S13, determining whether the pre-charging of the driving high-pressure circuit is completed, if so, executing step S14;

[0076] Step S14, close the driving main positive relay and open the driving pre-charge relay.

[0077] During the pre-charging process of the driving high-voltage circuit, the vehicle obtains the voltage difference at the collection point position on the circuit before and after the driving pre-charging relay is powered on, that is, the voltage difference between the rear end of the driving pre-charging resistor and the negative electrode of the battery unit. When the voltage difference is greater than the first preset value, it is determined that the driving high-voltage circuit pre-charging is completed, otherwise the driving high-voltage circuit pre-charging failure fault is reported to the vehicle. Among them, the first preset value is set according to the actual situation of the vehicle, and can generally be set to 0.95 times the output voltage of the battery unit.

[0078] The process of powering up the accessory high-voltage circuit includes:

[0079] Step S15, closing the accessory pre-charging relay;

[0080] Step S16, determining whether the pre-charging of the accessory high-voltage circuit is completed, if so, executing step S17;

[0081] Step S17, close the accessory main positive relay and open the accessory pre-charge relay.

[0082] During the accessory high-voltage circuit pre-charging process, the vehicle obtains the voltage difference at the collection point position on the circuit before and after the accessory pre-charging relay is powered on, that is, the voltage difference between the rear end of the driving pre-charging resistor and the negative electrode of the battery unit. When the voltage difference is greater than the second preset value, it is determined that the accessory high-voltage circuit pre-charging is completed, otherwise the accessory high-voltage circuit pre-charging failure fault is reported to the vehicle. Among them, the second preset value is set according to the actual situation of the vehicle, and can generally be set to 0.95 times the output voltage of the battery unit.

[0083] In this embodiment, during the power-on process of the whole vehicle in the non-charging state, the driving high-voltage circuit and the accessory high-voltage circuit are powered on in sequence. When the driving high-voltage circuit fails to be powered on, it means that the MCU or the motor has a high-voltage fault and needs to be turned off. Then the driving high-voltage prohibition mode is entered, that is, the motor output torque is controlled to be zero, and the driving high-voltage circuit is disconnected after the vehicle speed gradually drops to the preset vehicle speed threshold. The threshold can be set according to actual needs. At this time, the accessory high-voltage circuit works, that is, DC / DC, AC, PTC, etc. can be used normally; when the accessory high-voltage circuit fails, the accessory high-voltage prohibition mode is entered, that is, the high-voltage accessories are controlled to stop, and the current of the accessory high-voltage circuit drops to the current threshold. At this time, the whole vehicle still maintains the driving function until the battery power is low, and then the driving and power-off processing are prohibited. When both the driving high-voltage circuit and the accessory high-voltage circuit fail to be powered on, the whole vehicle is controlled to enter the prohibition of all high-voltage mode, that is, the whole vehicle is controlled to reduce high voltage, and all high-voltage components are prohibited from working, and driving is prohibited. Among them, the vehicle can reduce high voltage by disconnecting the total negative relay.

[0084] Based on the fault control method in the second embodiment, the fault mode process in the non-charging state in the embodiment of the present invention can be as follows: Figure 3 As shown, steps S111 to S123 are included:

[0085] Step S111, determining whether both the driving high-voltage circuit and the accessory high-voltage circuit are powered on successfully, if so, executing step S112, otherwise executing step S117.

[0086] Step S112, control the vehicle to enter the driving-allowed all high-voltage mode. The driving-allowed all high-voltage mode means that both the accessory high-voltage circuit and the driving high-voltage circuit are powered on in the non-charging state, and the high-voltage accessories and the drive system are allowed to operate normally.

[0087] Step S113, determine whether the driving high-pressure circuit is faulty, if so, execute step S114.

[0088] Step S114, controlling the vehicle to enter a driving-prohibited high-pressure mode.

[0089] Step S115, determine whether the accessory high-voltage circuit is faulty, if so, execute step S116.

[0090] Step S116, controlling the vehicle to enter a mode in which all high voltages are prohibited.

[0091] Step S117, determining whether the driving high-voltage circuit is powered on successfully and the accessory high-voltage circuit is powered on failed, if so, executing step S118, otherwise executing step S120.

[0092] Step S118, controlling the vehicle to enter a mode of disabling accessory high pressure.

[0093] Step S119, determine whether there is a fault in the driving high-voltage circuit, if so, execute step S116.

[0094] Step S120, determining whether the driving high voltage circuit fails to be powered on and the accessory high voltage circuit is powered on successfully. If so, executing step S121, otherwise executing step S123.

[0095] Step S121, controlling the vehicle to enter a driving-prohibited high-pressure mode.

[0096] Step S122, determine whether a high-voltage fault occurs in the accessory high-voltage circuit, and if so, execute step S116.

[0097] Step S123, determining whether the driving high-voltage circuit fails to be powered on and the accessory high-voltage circuit fails to be powered on, if so, executing step S116.

[0098] In this embodiment, in addition to monitoring high-voltage faults in the power-on link of the whole vehicle, after the whole vehicle is powered on, it will also detect in real time whether there are faults in the high-voltage driving circuit and the high-voltage accessory circuit that require high voltage to be reduced; when there is a fault in the high-voltage driving circuit that requires high voltage to be reduced, the whole vehicle is controlled to enter the said high-voltage driving prohibition mode; when there is a fault in the high-voltage accessory circuit that requires high voltage to be reduced, the whole vehicle is controlled to enter the high-voltage accessory prohibition mode; when faults occur in both the high-voltage driving circuit and the high-voltage accessory circuit, the mode of prohibiting all high voltages is entered.

[0099] That is, when the vehicle is in driving state and the driving high-voltage circuit and the accessory high-voltage circuit are connected, the treatment measures taken for various high-voltage faults are as follows:

[0100] When the MCU or motor has a high voltage fault, the power is cut off, the vehicle speed drops to the speed threshold, and the high voltage driving prohibition mode is entered. At this time, the high voltage accessories work;

[0101] When a high-voltage accessory has a high-voltage fault, the high-voltage accessory stops, the high-voltage circuit current of the accessory drops to the vehicle speed threshold, and the accessory high-voltage prohibition mode is entered;

[0102] When both the MCU / motor and high-voltage accessories have a high-voltage fault, the power is cut off and the vehicle speed drops to the vehicle speed threshold, the high-voltage main circuit is disconnected, and the mode of prohibiting all high voltages is entered;

[0103] When the MCU / motor and high-voltage accessories do not need to lower the high voltage, all high-voltage modes are allowed, and driving and high-voltage accessories work.

[0104] See also Figure 4 , is a fault control method based on the above-mentioned high-voltage control system in the third embodiment of the present invention, which is a control method when a high-voltage fault occurs in the power-on link under the charging state, including steps S21 to S28:

[0105] Step S21, detect whether the charging gun is connected, if so, execute step S22.

[0106] The charging gun on the charging pile is inserted into the slow charging port on the electric car, and the slow charging port is connected to the on-board charger. The on-board charger converts 220V AC power into DC power and charges the battery unit through the charging high-voltage circuit.

[0107] Step S22, whether the vehicle has a power-on request, if so, execute step S23.

[0108] Step S23, closing the total negative relay, the slow charging total positive relay and the accessory pre-charging relay in sequence.

[0109] Step S24, determine whether the accessory high-voltage circuit pre-charging is completed, if yes, execute step S25, otherwise, report the accessory high-voltage circuit pre-charging failure to the vehicle. During the accessory high-voltage circuit pre-charging process, the vehicle obtains the voltage difference between the rear end of the pre-charging resistor and the negative electrode of the battery unit before and after the accessory pre-charging relay is powered on, and when the voltage difference is greater than a second preset value, it is determined that the accessory high-voltage circuit pre-charging is completed.

[0110] Step S25, close the accessory main positive relay and open the accessory pre-charge relay.

[0111] Step S26, determine whether the charging high-voltage circuit and the accessory high-voltage circuit are both powered on. If so, report that the whole vehicle is powered on. Otherwise, execute step S27 or S28.

[0112] In specific implementation, it is determined whether the high voltage power-on of the charging circuit and the accessory high voltage circuit is completed according to the feedback status of the slow charging total positive relay and the accessory total positive relay.

[0113] Step S27, when the charging high voltage circuit fails to be powered on, the vehicle is controlled to enter a charging high voltage prohibition mode, wherein the charging high voltage prohibition mode is used to control the charging high voltage circuit to be disconnected, that is, the vehicle charging system stops working.

[0114] Step S28, when the accessory high voltage circuit fails to be powered on, the vehicle is controlled to enter an accessory high voltage disabled mode. The accessory high voltage disabled mode is used to control the accessory high voltage circuit to be disconnected and each high voltage accessory in the accessory unit to be shut down.

[0115] This embodiment is a high-voltage process when the whole vehicle is in a charging state. The whole vehicle sequentially powers on the charging high-voltage circuit and the accessory high-voltage circuit. When the charging high-voltage circuit fails to be powered on, it indicates that there is a high-voltage fault in the charging circuit that requires a high-voltage shutdown. The vehicle is controlled to enter a high-voltage charging prohibition mode, in which high-voltage accessories such as DC / DC, AC, and PTC can work normally. When the charging high-voltage circuit is powered on and the accessory high-voltage circuit fails to be powered on, the vehicle is controlled to enter a mode that prohibits all high-voltages. Among them, the mode that prohibits all high-voltages is to control all high-voltage components to shut down and disconnect the high-voltage main circuit. When the charging circuit high-voltage power-up is completed and the accessory high-voltage circuit is powered on, "vehicle high-voltage power-on is completed" is reported.

[0116] Based on the fault control method in the third embodiment, the fault mode process in the non-charging state in one embodiment of the present invention can be as follows: Figure 5 As shown, including:

[0117] Step S211, determine whether the charging high-voltage circuit is powered on successfully and the accessory high-voltage circuit is powered on successfully, if so, execute step S212, otherwise execute step S217.

[0118] Step S212, the vehicle may be controlled to enter a charging-allowed-all-high-voltage mode, wherein the charging-allowed-all-high-voltage mode means that both the charging high-voltage circuit and the accessory high-voltage circuit are powered on at high voltage in the charging state, and the high-voltage accessories and the charging system are allowed to operate normally.

[0119] Step S213, determine whether the charging high-voltage circuit is faulty, if so, execute step S214.

[0120] Step S214, controlling the vehicle to enter a charging prohibition high voltage mode.

[0121] Step S215, determine whether the accessory high-voltage circuit is faulty, if so, execute step S216.

[0122] Step S216, controlling the vehicle to enter a mode in which all high voltages are prohibited.

[0123] Step S217, determining whether the charging high-voltage circuit fails to be powered on and the accessory high-voltage circuit is powered on successfully, if so, executing step S218, otherwise executing step S220.

[0124] Step S218, controlling the vehicle to enter a charging prohibition high voltage mode.

[0125] Step S219, determine whether the accessory high-voltage circuit is faulty, if so, execute step S216.

[0126] Step S220, determining whether the charging high-voltage circuit fails to be powered on and the accessory high-voltage circuit fails to be powered on, if so, executing step S216.

[0127] In this embodiment, in addition to monitoring the power-on fault of the whole vehicle under charging state, it will also detect in real time whether there is a fault that requires high voltage reduction in the charging high-voltage circuit and the accessory high-voltage circuit after the whole vehicle is powered on. When a fault that requires high voltage reduction occurs in the charging high-voltage circuit, the charging high-voltage prohibition mode is entered, that is, the vehicle-mounted charging system is controlled to stop working; when a fault that requires high voltage reduction occurs in the accessory high-voltage circuit, the all high-voltage prohibition mode is entered, that is, the high voltage of the charging high-voltage circuit and the accessory high-voltage circuit is controlled to be disconnected, that is, the whole vehicle is low-voltage, and all high-voltage components are prohibited from working, and driving is prohibited.

[0128] See also Figure 6 , which is a high voltage power-down method in a non-charging state in a fourth embodiment of the present invention, including steps S31 to S34.

[0129] Step S31, when a high voltage power-off request is detected for the vehicle, the MCU and high voltage accessories are controlled to shut down through the VCU (vehicle controller);

[0130] Step S32, detect whether the power battery bus current is less than the calibration value, if so, execute step S33.

[0131] Step S33, disconnect the main negative relay, the driving main positive relay and the accessory main positive relay in sequence.

[0132] Step S34, when the high voltage disconnection is completed, the MCU is controlled to discharge the high voltage driving circuit, and the DC / DC is controlled to discharge the high voltage accessory circuit, and at the same time, the high voltage power-off completion is reported.

[0133] See also Figure 7 , which is a high voltage power-down method in a charging state in a fifth embodiment of the present invention, including steps S41 to S45.

[0134] Step S41, when it is detected that the vehicle has a high-voltage power-off request, the OBC is shut down by the BMS (battery management system), and the high-voltage accessories are shut down by the VCU.

[0135] Step S42, detect whether the power battery bus current is less than the calibration value, if so, execute step S43.

[0136] Step S43, disconnect the main negative relay and the accessory main positive relay in sequence.

[0137] Step S44, when the high voltage disconnection is completed, the DC / DC is controlled to discharge, and at the same time, the completion of the high voltage power-off of the whole vehicle is reported.

[0138] Step S45, when the DC / DC discharge is completed, disconnect the slow charging main positive relay.

[0139] Based on the high voltage control system of the present invention, a method for troubleshooting insulation faults is also provided. Figure 8 and Fig. 9 As shown, it is convenient for after-sales personnel or engineers to find the source of insulation fault in time and improve the efficiency of troubleshooting.

[0140] like Figure 8 As shown, insulation fault is eliminated in non-charging state: If insulation fault occurs in non-charging state, the auxiliary main positive relay can be disconnected through diagnosis or calibration equipment; then determine whether the insulation fault is eliminated; if the insulation fault is eliminated, it is located as an insulation fault in the auxiliary high-voltage circuit, and maintenance personnel can further check the insulation status of high-voltage components such as DCDC, PTC, and AC; if the insulation fault is not eliminated, it is located as an insulation fault in the driving high-voltage circuit, and maintenance personnel can further check the insulation status of the MCU and the motor.

[0141] like Fig. 9As shown, insulation fault is eliminated in charging state: If insulation fault occurs in charging state, the slow charging total positive relay can be controlled to disconnect through diagnosis or calibration equipment first; then determine whether the insulation fault is eliminated; if the insulation fault is eliminated, it is located as an insulation fault in the charging high-voltage circuit, and maintenance personnel can further check the insulation status of OBC and charging pile; if the insulation fault is not eliminated, it is located as an insulation fault in the charging circuit, and maintenance personnel can further check the insulation status of high-voltage accessories such as DCDC, PTC, and AC.

[0142] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0143] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0144] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0145] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0146] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A high-voltage control system, characterized in that: include: A driving high-voltage circuit, comprising a battery unit, a driving load unit connected to the negative electrode of the battery unit, and a driving pre-charging unit and a driving total positive relay connected in parallel between the driving load unit and the positive electrode of the battery unit, wherein the driving pre-charging unit is used to provide a pre-charge amount to the driving load unit; an accessory high-voltage circuit connected in parallel with the driving high-voltage circuit, comprising an accessory unit connected to the negative electrode of the battery unit, and an accessory main positive relay and an accessory pre-charging unit connected in parallel between the positive electrode of the battery unit and the accessory unit, the accessory pre-charging unit being used to provide a pre-charge amount to the accessory unit; A charging high-voltage circuit, connected to the rear end of the accessory high-voltage circuit, comprising a slow-charging total positive relay and an on-board charging system, wherein the input end and the output end of the slow-charging total positive relay are respectively connected to the output end of the accessory total positive relay and the on-board charging system, and the on-board charging system is connected to the negative electrode of the battery unit, wherein the travel load unit comprises a high-voltage component for driving the vehicle, and the accessory unit comprises a high-voltage component in a vehicle accessory; It also includes a total negative relay, one end of which is connected to the battery unit, and the other end of which is respectively connected to the driving load unit, the accessory unit and the input end of the vehicle charging system; The running pre-charging unit comprises a running pre-charging relay and a running pre-charging resistor connected in series, the running pre-charging relay is connected to the battery unit, and the running pre-charging resistor is connected to the running load unit; The accessory pre-charging unit includes an accessory pre-charging relay and an accessory pre-charging resistor connected in series, the accessory pre-charging relay is connected to the battery unit, and the accessory pre-charging resistor is connected to the accessory unit.

2. The high-voltage control system according to claim 1, characterized in that: It also includes a plurality of fuses, which are respectively connected to the input ends of a plurality of high-voltage accessories.

3. The high voltage control system according to claim 1, characterized in that: The travel load unit includes an MCU and a motor connected to the MCU.

4. The high-voltage control system according to claim 1, characterized in that: The accessory unit includes a DC / DC converter, an air-conditioning electric heater, an air-conditioning compressor and a battery heater.

5. A fault control method, characterized in that: Applied to the high-voltage control system according to any one of claims 1 to 4, the fault control method comprises: Check whether the charging gun is connected; When the charging gun is not connected and it is detected that the vehicle needs to be powered on, the driving high-voltage circuit and the accessory high-voltage circuit are powered on respectively; When the driving high-voltage circuit fails to be powered on and the accessory high-voltage circuit is powered on successfully, the vehicle is controlled to enter a driving high-voltage prohibition mode, wherein the driving high-voltage prohibition mode is used to control the driving high-voltage circuit to be disconnected and control the motor output torque to be zero; When the driving high-voltage circuit is powered on successfully and the accessory high-voltage circuit fails to be powered on, the vehicle is controlled to enter an accessory high-voltage prohibition mode, wherein the accessory high-voltage prohibition mode is used to control the accessory high-voltage circuit to be disconnected and control each high-voltage accessory in the accessory unit to be shut down; When both the driving high-voltage circuit and the accessory high-voltage circuit fail to be powered on, the entire vehicle is controlled to enter a mode of disabling all high-voltage circuits, wherein the mode of disabling all high-voltage circuits is to control all high-voltage circuits to be disconnected and all high-voltage components to be shut down.

6. The fault control method according to claim 5, characterized in that: The method further comprises: When the charging gun is connected and it is detected that the vehicle needs to be powered on, the charging high-voltage circuit is powered on; When the charging high-voltage circuit is powered on successfully, the accessory high-voltage circuit is powered on; When the charging high-voltage circuit fails to be powered on, the vehicle is controlled to enter a charging high-voltage prohibition mode, wherein the charging high-voltage prohibition mode is used to control the charging high-voltage circuit to be disconnected; When the charging high-voltage circuit is powered on successfully and the accessory high-voltage circuit fails to be powered on, the entire vehicle is controlled to enter the all-high-voltage mode.

7. The fault control method according to claim 5, characterized in that: The method further comprises: When the driving high-voltage circuit and the accessory high-voltage circuit are both powered on successfully, real-time detection is performed to determine whether there are faults on the driving high-voltage circuit and the accessory high-voltage circuit that require high voltage reduction; When a fault that requires high pressure is present in the driving high pressure circuit, the vehicle is controlled to enter the driving high pressure prohibition mode; When a fault occurs in the accessory high-voltage circuit that requires high voltage to be lowered, the entire vehicle is controlled to enter the accessory high-voltage prohibition mode.

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